var listFrom = project.Lists["Lists1"];
var listTo = project.Lists["Lists2"];
var listTo1 = project.Lists["Lists3"];
listTo.AddRange(listFrom);
listTo1.AddRange(listFrom);
var listFrom = project.Lists["Lists1"];
var listTo = project.Lists["Lists2"];
var listTo1 = project.Lists["Lists3"];
listTo.AddRange(listFrom);
listTo1.AddRange(listFrom);